The present invention relates to the area of chip removing machining and then especially to a milling insert and a milling tool. The milling insert is indexably mounted in the milling tool. The milling tool is an end mill having 90° setting angle.
Upon tangential mounting of trigon inserts in a milling body as in applicants WO2007149035, the insert seats formed in the milling body of the milling tool have a trigon shape adapted to the cutting insert, as seen in planar view of the insert seat. The trigon shape of the insert seats entails that certain of the flanks of the milling body that surround the cutting insert comprise relatively little material, i.e., the flanks become weak as for carrying the loads.
So-called triangular cutting inserts are generally known. A disadvantage of these cutting inserts is that they have weak cutting corners.
It is desirable to provide a cutting insert and a tool for chip removing machining of the kind defined by way of introduction, the critical flanks of the milling body not being weakened in comparison with prior tools.
It is also desirable to provide the cutting insert with a maximum number of cutting edge areas, in this case the number of areas being six.
It is also desirable to improve the mutual support function between the cutting insert and the insert seal formed in the milling body.
It is also desirable that the cutting insert is given such a positioning in the cutting body that the cutting insert does not interfere with the machined surface that is obtained during milling using the tool according to the present invention.
According to an aspect of the present invention, an indexable milling insert having triangular shape is provided, the cutting insert comprising a mounting hole placed centrally in the cutting insert, a first support surface and a second support surface, which support surfaces are parallel with each other and act as alternating support surfaces, that the cutting insert comprises three equally long sides, which extend between the parallel support surfaces, that the cutting insert is provided with main cutting edges, which are orientated perpendicularly to the center axis of the mounting hole as well as provided in such a way that a rotation of the cutting insert around the center of the mounting hole to an alternative insert seal alternatively a turning of the cutting insert to an alternative insert seat provides an identical location of the main cutting edges in relation to a piece to be machined, and that the wedge angles (β) of the cutting insert are in the range of 70°≦β≦85°, wherein the cutting insert comprises planar support surfaces situated on the sides, and that the support surfaces in the respective sides form mutual angles of 60°.
According to another aspect of the present invention, a milling tool comprises a milling body having a plurality of insert seats, wherein each insert seat is configured to receive a milling insert as described above so that the milling inserts are tangentially mounted in the milling body.